// http://paulirish.com/2011/requestanimationframe-for-smart-animating/
// http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating

// requestAnimationFrame polyfill by Erik Möller
// fixes from Paul Irish and Tino Zijdel

(function() {

var lastTime = 0;
var vendors = ['ms', 'moz', 'webkit', 'o'];

for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) 
{
  window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
  window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame']
  window[vendors[x]+'CancelRequestAnimationFrame'];
}
 
if (!window.requestAnimationFrame)
  window.requestAnimationFrame = function(callback, element) {
  var currTime = new Date().getTime();
  var timeToCall = Math.max(0, 16 - (currTime - lastTime));
  var id = window.setTimeout(function() { callback(currTime + timeToCall); }, timeToCall);
  lastTime = currTime + timeToCall;
  return id;
};
 
if (!window.cancelAnimationFrame)
{
  window.cancelAnimationFrame = function(id) 
  {
    clearTimeout(id);
  };
}

}());